Contact selector



June 9, 1942. w H sTARcK 2,286,022

CONTACT SELECTOR Filed Oct. 14, 1940 j mu 'y INVENTOR ATTORNEYS PatentedJune 9, 1942 UNITED STATES PATENTy OFFICE CONTACT SELECTOR William H.Starck, West Chicago, Ill.

Application October 14, 1940, Serial No. 361,181

(Cl. ZOO- 6) 3 Claims.

This invention relates in general to improvements in electricalswitching means and especially is concerned with a novel electric switchadapted for operation by an oscillating cam.

It is an object of this invention to provide a sensitive electriccurrent control means for use in conjunction with railroad signals ofthe socalled wigwag type.

Another object of this invention is to provide an electrical switchadapted for operation by an oscillating cam which will indicate currentcontrol changes in direction of motion.

A still further object of this invention is to provide an electricalswitching means operating by an oscillating cam indicating both changein direction of motion which is extremely sensitive from a practicalstandpoint and which includes means for magnifying such changes ofmotion as occur further to promote delicate sensitivity and nicety ofadjustment.

An advantage of the novel switch construction according to thisinvention over similar electrical switches now in use is that in it lostmotion is reduced substantially to a minimum with the result that aswitch functions substantially in- 1 stantaneously to indicate changesin direction of motion of the cam by which the switch is operated.

Noteworthy among the features of the novel switch according to thepresent invention are its ifi simplicity and ruggedness of construction,the former suiting the device to the requirements of manufacture underconditions of mass productionand the latter assuring long useful life.

Other objects, advantages and features of the .t

near its bottom end to the first bar at a place Y' intermediate the axisof swinging motion of said first bar and a distal end thereof wherebyoscillation of the first bar in a vertical plane causes verticalreciprocation of the secon-d bar, a rigid rider on the bottom of thesecond bar frictionally engaging with the operating cam in a manner suchthat changes in the position of the cam causes vertical reciprocation ofthe second bar and swinging of the first bar and changes in direction ofmotion of the cam cause oscillation of the second bar about the pivotalconnection to the first bar, and switches operated by swinging of eachof said bars.

In order to facilitate a fuller and more complete understanding of thepresent invention a specic embodiment thereof herein illustrated will behereinafter described, it being clearly understood, however, that theillustrated embodiment, although presently preferred, is provided solelyby way of example of the practice of this invention and not by way oflimitation thereof except insofar as the invention is recited in thesubjoined claims.

Referring now to the drawing,

Figure 1 is substantially a front elevational View of the presentlypreferred embodiment of this invention showing the same mounted adjacentan operated cam,

Fig. 2 is essentially a side elevational view of the device in Fig. 1,and

Fig. 3 is a top plan View thereof.

The herein illustrated presently preferred embodiment of this inventiongenerally designated by the reference character IIJ comprises, it willbe noticed, an electrical insulative base II upon which is mounted bymeans of a pin I2 and spacer sleeve I3 a horizontally positionedvertically swingable first bar I4. It is to be noticed that the pin I2is received in the first bar I4 near one end thereof and that the firstbar is held in position thereon by a Cotter pin I2a. A verticallyadjustable L-shaped member I5 mounted upon the base Il by screws I6 isdisposed in a manner such that a portion I5a thereof extends beneathand, upon occasion, can support the first bar I4 to limit downwardswinging motion thereof.

A substantially vertical second bar I1 pivoted near its bottom end by apin i8 to the first bar I4 at a place intermediate the pin I2 and thedistal free end of the first bar is held in spaced relationship withrespect to the base II in a manner permitting free verticalreciprocation and oscillation in a Vertical plane parallel to the planeof swinging motion of the first bar I4. A rider 20 rigidly mounted onthe bottom of the second bar I1 frictionally engages with the surface Aof a cam B fixedly mounted upon an oscillating shaft C, it beingunderstood that the rider is continually appressed against the camsurface A by action of gravity upon the as sembly comprising the bars I4and I'l.

An intrinsically resilient arm 2| mounted near the distal free end ofthe bar I4 by means of a screw 22 extends upwardly and in spacedadjacency over the bar end substantially as shown and carries on itsfree end a contact element 23 suited to making electrical contact withan end portion 24 of a screw 25 adjustably mounted in a bracket 26 andheld in position by a locknut 21. In practice the screw 25 is advancedin the bracket 26 until electrical contact is established between thescrew end 24 and the contact element 23, when the cam B is in theintermediate position illustrated in full line in Fig. 1, that is tosay, when the bar I4 is at its maximum height during the cam motion.

An electrically conductive bar 28 mounted upon an insulative base II iselectrically connected to the bar by a flexible cable 29 and is providedat its opposite end with a terminal screw 33 for facilitating connectingof an electrical cable to the switch, and in like manner a lug 3l is-connected to the screw 25 by being positioned under the adjustment nut21. It will follow from what has been set forth above that an electricalcircuit may be completed or interrupted through the contact element 23on the arm 2| and the screw head 24 and thus an electrical circuitincluding the terminal 33 and 1 ards 38 and 39 attached to the base IIby screws 40 and locked in position by nuts 4I and 42 respectively arepositionable in a manner such that the heads 43 and 44 respectively ofsaid screws 36 and 31 act as stops limiting the motion of the ball 35resulting from oscillation of the arm I1 due to changes in direction ofmotion of the cam B. As will be obvious from the foregoing statements,oscillation of the cam causes the electrical contacting of the ball 35alternately with the screw heads 43 and 44 and, accordingly, theelectrical circuits including the terminal 30 and the screws 36 and 31intermittently are completed and interrupted. For facilitatingconnection of electrical cables to the screws 36 and 31, lugs 45 and 43are respectively provided.

Having thus described the construction of the novel switching meansaccording to the present invention, its preferred mode of useillustrated by its use in conjunction with a railroad signal of thewigwag type will now be described. In this instance the shaft C isconnected to the pendulum signal which is oscillated by means such as apair of magnets, one positioned on each side of a vertical planeintersecting the axis of the shaft cooperating with an armature mountedupon the shaft extending in a vertical position when the pendulum signalis at rest. The pendulum is set in motion by alternate energization ofthe magnets which in turn oscillates the armature with concomitantoscillation of the shaft and of the signal. For this purpose theelectromagnets are connected to the screws 3G and 31, it beingunderstood of course that the terminal 36 is connected to one side ofthe power supply line complementary to the side of the power supply linefeeding the electromagnets whereby, when the ball 35 is positionedagainst one or the other of the screw heads 43 and 44, an electromagnetis placed in circuit with the power supply. It is to be understood thatthe electromagnet in each instance connected to the power supply is theone which will tend to move the armature from its position at the timeof connection.

As will be apparent from the detailed description of the structure ofthis invention, oscillation of the cam B results in oscillation of thebar I1 by reason of frictional engagement of the rigid rider 20 with thecam surface A. It is to be noticed that the distance between the pivotpin I8 and the cam surface upon which the rider rests is small inproportion to the distance between the pivot pin and the ball 35. Thusrelatively small movement of the rider is reflected in relatively largeor magnified movement of the ball. This feature promotes sensitivity ofthe device since change of direction of motion of the cam issubstantially instantaneously reflected in oscillation of the bar. Theswitch comprising the contact element 23 and the screw head 24 is usefulin controlling the operation of audible or physical signalling meansfunctioning in conjunction with the wigwag signal. It is to be noticedthat the circuit is completed through the switch only when the cam B islocated in its intermediate positionA as shown in full line in Fig. l,or in other words, the circuit including the switch is interrupted whenthe bar I4 descends due to the contour of the cam B near the endsthereof. l

It is t0 be noticed that the ball 35 is vertically reciprocated duringoscillation of the cam and hence it will be apparent to those skilled inthis art that electrical contact between the ball and the screw heads 43and 44 -will be promoted because of wear of the parts resulting in cleancontact surfaces.

It is to be understood that this invention is capable of extendedapplication and is not confined to the precise illustrated forms nordescribed construction and, therefore, such changes and modications maybe made therein as do not affect the spirit of the invention nor exceedthe scope of the appended claims.

Having thus described the present invention, what it is desired tosecure by Letters Patent is:

1. A switch of the character described, comprising a vertically disposedbase, a horizontally arranged bar pivoted at one end, an electriccontact carried by the base above the free end of the bar, a verticallyarranged bar intermediately pivoted to the horizontally arranged bar,electrical contacts carried by the base on opposite sides of the upperend of the vertically arranged bar for completing a circuit through thebar by the movement thereof in either direction, and a movable cam forengaging the lower end of the vertically arrangedcbar Afor swinging thesame on its pivot and simultaneously causing the horizontally arrangedbar to complete a circuit.

2. A switch of the character described, comprising a vertically disposedbase, a horizontally arranged bar pivoted at one end, an electriccontact carried by the base above the free end of the bar, a springcontact carried by the free end of the bar and adapted to engage thefirst mentioned contact, a vertically arranged bar intermediatelypivoted to the horizontally arranged bar intermediate its ends,electrical contacts carried by the base on opposite sides of the upperend of the vertically arranged bar for completing a circuit through thebar by the movement thereof in either direction, and a movable cam forengaging the lower end of the vertically arranged bar for swinging thesame on its pivot and causing it to engage the contacts andsimultaneously causing the horizontally arranged bar to make contactwith the Contact on the base upon the upward movement thereof.

3. A switch of the character described, cornprising a verticallydisposed base, a horizontally arranged bar pivoted at one end to thebase, an electric contact carried by the base above the free end of thebar, a spring contact carried by the upper face of the bar and adaptedto engage the first mentioned contact, a vertically arranged barintermediately pvoted to the horizontally arranged bar intermediate itsends, a Contact carried by the base on each side 0f the upper end of thevertically arranged bar for completing a circuit through the bar by themovement thereof in either direction, and an oscillating cam forengaging the lower end of the vertically arranged bar for swinging thesame on its pivot to cause the bar to engage either of the contacts andsimultaneously raising the horizontally arranged bar to cause its SpringContact to engage the contact on the base.

WILLIAM H. STARCK.

